A field survey was conducted on Miyako islands, including Irabu island, Miyako island, Kurima island and Ikema island on June 25 and 26 in 2024, to confirm the preservation of previously explored sites for Vigna marina (Burman) Merrill and Vigna riukiuensis (Ohwi) Ohwi & Ohashi. A total of 11 sites including 16 habitats for V. marina and 2 habitats for V. rirukiuensis were surveyed and all sites were found positive in accommodating the populations.
Wang et al. (Sat,) studied this question.